Cleveland police Monday afternoon said that the manhunt for Steve Stephens, the suspect in a shooting death posted to Facebook Sunday, is now a “national search."

A reward of $50,000 is being offered for information leading to Stephens' arrest, Cleveland Mayor Frank G. Jackson said. A manhunt was launched after police were alerted to a video posted to Facebook around 2 p.m. Sunday in which Stephens approaches 74-year-old Robert Godwin and asks him to say the name of a woman, believed to be Stephens' former girlfriend. He then appears to point a gun to Godwin's head and shoots him.

"Our reach now is all over this country. This is a national search. We are not going to leave any stone unturned," police Chief Calvin Williams said.

Williams said that police had searched the home where Stephens, 37, lived and had found weapons. “We can say without a doubt he’s armed,” the chief said.

Despite expanding the search, Williams said that there was no evidence that Stephens was now out of Ohio. Police had earlier expanded their search into four other states—Pennsylvania, Indiana, Michigan and New York—and warned residents to be on alert.

Stevie Steve

A man who identified himself as Stevie Steve is seen in a combination of stills from a video he broadcast of himself on Facebook in Cleveland, Ohio, April 16, 2017. Stevie Steve/Social Media/ Handout via Reuters

One of Cleveland police's detectives had spoken to Stevens following the murder, Williams said, but that was the last known contact with him. He didn't confirm a statement from Pennsylvania authorities to CNN that Stephens’ cell phone had “pinged” in Erie, Pennsylvania.

Around 400 miles away from Erie, in Philadelphia, there were reports that Stephens was in Fairmount Park, leading to several schools in the area being placed on lockdown. However, Philadelphia police said Monday afternoon that “there is no indication that the subject is at that location or anywhere in the city of Philadelphia.”

Godwin was reportedly walking him from Easter lunch when he was killed. He was believed to have been targeted at random.

Stephens boasted in another video that he had killed 13 other people and would continue to kill more. However, police said Monday morning they were not aware of any other victims.

Stephens’ mother, Maggie Green, told CNN that she had spoken to her son Sunday, saying he told her that he was “mad with his girlfriend. That's why he is shooting people and he won't stop until his mother or girlfriend tell him to stop.”